<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>p3_边框</title>
    <style>
        .d1{
            width: 200px;
            height: 200px;
            background-color: #0aa1ed;
            border: 5px solid #f00;
            border-top: 5px dotted #ff0;
            border-radius: 100px;
        }
        .d2{
            width: 200px;
            height: 200px;
            background-color: pink;
            border: 5px solid magenta;
            padding-left: 50px;
            padding-top: 50px;
            margin: 50px;
            box-sizing: border-box;
        }
        span{
            border: 3px solid #f00;
        }
        .s2{
            padding:50px;
        }
    </style>
</head>
<body>
<div class="d1">

</div>
<div class="d2">
    内间距测试
</div>
<span>span1</span><span class="s2">span2</span><span>span3</span>
</body>
</html>